Decarboxylation, that is, elimination of the --COOH group as CO.sub.2, is a known process. March, J., Advanced Organic Chemistry: Reactions, Mechanisms, and Structure, 1968, pp. 435-436, 477-480 and 878-879, describes various decarboxylation reactions. At pages 435-436, it is stated that aromatic acids can be decarboxylated by heating with copper and quinoline. At pages 477-480, it is stated that aliphatic acids which undergo successful decarboxylation have certain functional groups or double or triple bonds in the alpha or beta positions such as malonic acids, alpha-cyano acids, alpha-nitro acids, alpha-aryl acids, alpha-keto acids, alpha-trihalo acids, beta-keto acids, beta,gamma-olefinic acids and the like. At pages 878-879, oxidative decarboxylation is described in which lead tetraacetate cleaves carboxyl groups, replacing them with acetoxy groups, which may be hydrolyzed to hydroxyl groups. It is stated that compounds containing carboxyl groups on adjacent carbons (succinic acid derivatives) can be bisdecarboxylated with lead tetraacetate. It is also stated that compounds containing geminal carboxyl groups (malonic acid derivatives) can be bisdecarboxylated with lead tetraacetate, gem-diacetates (acylals) being produced, which are hydrolyzable to ketones.
Tundo, Pietro et al., Ind. Eng. Chem. Res., 1988, 27, 1565-1571, describes the reaction of dialkyl carbonates with phenols, thiophenols and mercaptans under gas-liquid phase-transfer conditions (continuous flow of gaseous reactants over a solid bed supporting a liquid phase-transfer catalyst) to produce the corresponding ethers and thioethers. The solid bed consisted of potassium carbonate coated with 5 weight percent of CARBOWAX.RTM. poly(oxyethylene)glycol 6000 for one set of experiments and alpha-alumina pellets coated with 5 weight percent of potassium carbonate and 5 weight percent of CARBOWAX.RTM. poly(oxyethylene)glycol 6000 for another set of experiments. Tundo et al. state at page 1568, right hand column, lines 33-42, that the reaction of alcohols with dialkyl carbonates produces only transesterification.
Triethylenediamine, also referred to as 1,4-diazabicyclo[2.2.2]octane or DABCO, is an item of commerce which is used as a catalyst for --OH+OCN--reactions to form the urethane linkage in polyurethanes.
Various processes for the production of triethylenediamine are known For example, triethylenediamine may be produced by the method disclosed in WO 87/03592, published Jun. 18, 1987. As disclosed therein, triethylenediamine may be produced by bringing an amine compound having a specific amino group into contact with a crystalline metal silicate catalyst wherein the molar ratio of silicon dioxide (SiO.sub.2) to an oxide of a trivalent metal (M.sub.2 O.sub.3 :M being a trivalent metal) is 12 or more.
European Patent Application No. 0158319, published Oct. 16, 1985, discloses a method for preparing 1,4-diazabicyclo[2.2.2]octanes by contacting acyclic or heterocyclic amines with a high-silica zeolite having a silica to alumina ratio of at least 20 to 1.
European Patent Application No. 0263463, published Apr. 13, 1988, discloses a method for preparing 1,4-diazabicyclo[2.2.2]octane and C-substituted 1,4-diazabicyclo[2.2.2]octane by reacting a particular heterocyclic amine in the presence of L-zeolites, phosphates with zeolite structure and zirconium phosphates as catalysts.
Romanian Socialist Republic Specification 85563 discloses a process for the preparation of triethylenediamine characterized by the fact that N,N-dihydroxyethylpiperazine is cyclized in the gaseous phase on an alumina catalyst alkalized with a base chosen from alkali or alkaline earth hydroxides in an amount of from 0.01-10 weight percent based on alumina at a reaction temperature between 200.degree. C. and 550.degree. C., preferably 300.degree. C.-450.degree. C., and an operating pressure between 0.1 and 10 atmospheres
Copending U.S. patent application Ser. No. 282,371, filed Dec. 13, 1988, now abandoned, relates to processes for the production of amines, more specifically, to processes for preparing triethylenediamine and/or one or more cyclic or acyclic amines by contacting one or more amine starting materials with one or more molecular sieves. By proper choice of catalysts and/or reaction conditions, the processes can be varied to alter their selectivity to a number of differing and useful products, including triethylenediamine and substituted triethylenediamines.